One dispenser for sheets of note paper in such a stack (i.e., "Scotch" brand "Post-it" Note Pads commercially available from Minnesota Mining and Manufacturing Co., St. Paul, Minn.) is described in U.S. Pat. No. 4,416,392 assigned to the assignee of this application, wherein the stack of sheets is disposed in a box and the sheets can be withdrawn through a slot in the top of the box and centrally disposed parallel to the opposite edges of the sheets which are coated with the bands of adhesive. The box described in U.S. Pat. No. 4,416,392, however, provides no means for preventing the second sheet in the stack from being withdrawn with the first sheet in the stack in response to force applied to the first sheet to withdraw it. Thus, to separate the first sheet from the second after the first sheet is withdrawn from the box, the first sheet must be manually peeled from the second while manually holding the second sheet, which is inconvenient.
U.S. Pat. No. 4,416,392 also describes a dispenser for such a stack of sheet material wherein a base is provided for supporting a removable cover within which is disposed the stack of sheet material. The cover is provided with an opening in its top wall and the stack of sheets is urged toward the top wall by a spring. The top wall is formed by two inclined portions which terminate at the dispensing opening. While the spring in this dispenser provides means for preventing the second sheet in the stack from being withdrawn with the first sheet in the stack in response to force applied to the first sheet to withdraw it due to the pressure the spring provides between the second sheet and the top wall, this dispenser comprises four basic parts to dispense the stack of sheets, and the sharp edges in the dispenser at the opening cause sheets that are dispensed to become stressed during the dispensing action about the edges of the opening so that the sheets retain a curl after they are dispensed.
Subsequent non commercialized attempts to provide improved dispensers from such a stack of note paper are described in U.S. Pat. Nos. 4,562,938, 4,586,629, 4,586,630, and 4,586,631 assigned to the assignee of this application.
U.S. Pat. No. 4,653,666, assigned to the assignee of this application, discloses a further embodiment of a dispenser for such a stack of sheets which has been commercialized. This dispenser comprises a box which fits about the stack of sheets and has a centrally disposed opening transverse to the edges coated with the adhesive. A spring member in the box presses the stack of sheets toward the opening. Extending from the top wall of the box and into the opening are flexible polymeric flaps which during dispensing of the sheets bend to form convex arcuate surfaces about which the sheets are drawn as they are dispensed. This structure thus avoids the development of any curl in the dispensed sheets so that the sheets, after being dispensed and positioned on a receptor lay generally flat along the surface of the receptor and thus are not as subject to becoming dislodged as they would be had a curl been present in the dispensed sheet. This dispenser, as noted however, comprises a number of parts.
U.S. Pat. No. 4,921,127 also assigned to the assignee of this application, describes refillable dispensers for such a stack of sheets comprising a base part adapted to be supported on a horizontal support surface and to support the stack of sheets; and a body part having a bottom surface including spaced pressure surface portions adapted to engage and be supported on the upper surface of the stack adjacent the edges of the sheets along which the narrow bands of adhesive are coated with the spaced pressure surface portions engaging an upper surface of the sheets at predetermined distances from the edges of the sheets along which the narrow bands of adhesive are coated, and convex arcuate surface portions between the pressure surface portions and a top surface of the body part defining a slot through and extending centrally across the body part. The convex arcuate surface portions have radii having a dimension at least as great as the predetermined distances to restrict curling of sheets of paper pulled from the dispenser through the slot, and the body part has sufficient weight (e.g., about 0.5 to 1.5 pound) to afford pulling a sheet from the stack through the slot without substantially lifting the body part from the stack.
U.S. Pat. No. 4,993,590 also assigned to the assignee of this application, describes a refillable dispenser for such a stack of sheets adapted to be attached to a surface and having a top wall including spaced pressure surface portions adapted to engage the upper surface of the stack at predetermined distances from the edges of the sheets along which the narrow bands of adhesive are coated to define a slot through and extending centrally across the body part through which the sheets are withdrawn, which dispenser arcs the stack to facilitate withdrawal of the sheet, and includes means for pressing the stack against its top wall.
A dispenser for polymeric sheets in such a stack (i.e., "Post-it" brand Tape Flags commercially available from Minnesota Mining and Manufacturing Co., St. Paul, Minn.) is described in U.S. Pat. No. 4,770,320 assigned to the assignee of this application, wherein the stack of sheets is disposed in a dispenser and the sheets can be withdrawn through a slot in the top of the dispenser that is centrally disposed parallel to the opposite edges of the sheets which are coated with the bands of adhesive. The dispenser described in U.S. Pat. No. 4,770,320 provides shuttling of the stack of sheets back and forth in the dispenser to preventing the second sheet in the stack from being withdrawn with the first sheet in the stack in response to force applied to the first sheet to withdraw it.
While several of the dispensers described in the U.S. Patents described above are effective in allowing sheets to be withdrawn from the stack without either curling or wrinkling the sheets and without withdrawing the second sheet in the stack with the sheet being withdrawn, there is an ongoing effort to provide develop new dispensers for sheets from such a stack.